So, er, could someone answer my question? What's the poster all about and how do we get involved? Thanks..
Lord Erwin, when you are here in the forums go to the section labeled "Community Activities". There you will find the weekly activities that you can participate in. The most popular of these is the Creature of the Week, or C.O.W. as we know it. This poster contains the work of the 400 artists who entered artwork for the first 50 rounds.
To get involved, simply check the thread to see what the current topic is, and submit original artwork which meets the criteria and follows the rules before the deadline. As long as your piece is accepted (most submissions are), you will be cast into the voting stage and people can vote for your piece if they feel it is the best for the week, and you can vote for other entries.
There are also Character of the week, Environment of the Week, Industry Design, and 3CH / Random Topic activities.
Hope this helps you out, hope to see you in the weeklies!